A pharmacokinetic study of droperidol was performed in ten anesthetized patients receiving an intravenous bolus dose of 150 μg/kg of droperidol. Plasma concentrations were measured using a specific radioimmunoassay method. The pharmacokinetics of droperidol can be described according to a three-compartment open model. The mean (±SD) half-life for the rapid (t1/2π) and slow distribution (t1/2α) phases was 1.4 ± 0.5 min and 14.3 ± 6.5 min, respectively. The mean elimination half-life, t1/2 β was 103.8 ± 20.2 min. The mean (±SD) total body clearance was 14.1 ± 4.4 ml · min−1· kg−1, and the total apparent volume of distribution (Vdβ) was 2.04 ± 0.50 1/kg. The short terminal half-life of droperidol does not correlate with the well-known, relatively prolonged duration of its pharmacologic action.